Large Ground Grid Ground Resistance Tester – Variable Frequency Anti-Interference

Large-scale Grounding Grid Resistance Tester

The MEDW-W5A Large Ground Grid Ground Resistance Tester is a high-precision instrument designed for grounding resistance and related parameter testing in substations, power plants, and other industrial field applications. This integrated unit features a built-in variable frequency power module with continuously adjustable output from 45Hz to 55Hz. By utilizing advanced digital filtering technology and a high-speed DSP processor, the MEDW-W5A effectively eliminates power frequency (50Hz) electromagnetic interference, ensuring accurate and repeatable measurements even in harsh live substation environments. With a maximum output current of 5A and a measurement resolution of 0.0001Ω, this ground resistance tester delivers reliable data for large-scale grounding grid evaluation. Lightweight at only 22kg, it significantly reduces onsite labor intensity and testing time.

The MEDW-W5A is shipped complete with all necessary accessories for immediate field use. No additional purchase is required.

1. Dual-Frequency Variable Frequency Technology – Eliminates Interference
The MEDW-W5A operates at 45Hz and 55Hz test frequencies, completely avoiding 50Hz power frequency interference. Field tests confirm that even when interference voltage on the potential lead reaches 10V and interference current on the current lead reaches 1A, the instrument still delivers stable, accurate readings. This ensures measurement integrity in live 500kV substations where traditional methods fail.

2. High-Precision DSP Processing – Reliable Low-Resistance Measurement
Equipped with a professional-grade high-speed digital signal processor, the MEDW-5A achieves 0.0001Ω resolution with an accuracy of ±(1% reading + 0.002Ω). This high precision is critical for measuring large grounding grids where resistance values often fall below 0.5Ω, preventing misjudgments that could lead to safety hazards.

3. Lightweight Integrated Design – Reduces Onsite Labor
Unlike traditional power-frequency testers that require bulky 30A+ current sources weighing hundreds of kilograms, the MEDW-5A integrates a variable frequency power module weighing just 22kg. The unit delivers a maximum 5A test current, sufficient for all large grounding grid measurements. One technician can easily transport and operate the instrument, cutting testing time and labor costs by over 50%.

4. Fully Touchscreen Interface – Zero Training Required
The large graphical touchscreen LCD displays every step of the measurement process. Operators simply follow the on-screen wiring diagrams and touch the "Start Test" button. No specialized training is required, making field testing efficient even for non-expert personnel.

5. Built-in Data Storage & U Disk Export
The instrument stores up to 100 test records with time stamps via its built-in calendar chip. Data can be exported directly to a U disk as a date-named text file, then viewed or generated into reports using the included PC software. This simplifies documentation and audit trail management.

- Substation grounding grid acceptance testing

- Power plant grounding system evaluation

- Lightning protection system verification

- Telecommunication base station grounding inspection

- Railway and airport grounding infrastructure

- Industrial facility grounding audits

More About Us

Why Choose Us as Your Ground Resistance Tester Manufacturer?

1. ISO 9001:2015 Certified Production Facility

Our manufacturing plant operates under strict ISO 9001:2015 quality management standards. Every MEDW-5A unit undergoes a 48-hour high-temperature burn-in test and precision calibration against reference standard resistors before shipment, ensuring long-term reliability and measurement accuracy.

2. In-House R&D and Engineering Team

We develop and manufacture all core components in-house, including the variable frequency power module and DSP control board. This vertical integration allows us to maintain strict quality control over every production stage and respond quickly to custom requirements.

3. Traceable Calibration and Quality Records

Each instrument ships with an individual factory calibration certificate traceable to national standards. Our testing equipment is regularly calibrated by third-party metrology laboratories, guaranteeing that every unit meets the accuracy specifications stated in the manual.

4. Global Compliance and Certifications

Our ground resistance testers comply with international safety and performance standards, including CE marking for European markets. We also strictly adhere to DL/T 475-2016 and JJG 366-2004 Chinese metrology regulations.

5. Reliable Supply Chain and Fast Delivery

With a monthly production capacity of over 200 units and strategic inventory of key components, we ensure lead times of 7-15 days for bulk orders, even during peak seasons.

6. Dedicated After-Sales Support

We provide one-year warranty and lifetime technical support. Our engineering team offers remote troubleshooting, spare parts replacement, and optional third-party calibration services to keep your equipment performing optimally throughout its service life.

production site

manufacturing scenario